Electric switch



June 17, 17941. Q P, PEPPER 2,246,183

' ELECTRIC SWITCH Filed May 4,v 1959 Figi Figli.

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Patented June 17,' 1941 UNITED STATES PATENT OFFICEy 2,246,183 ELECTRICSWITCH Carl P. Pepper, Fort Wayne, Ind., assignor to General ElectricCompany, a corporation of New York Application May 4, 1939, Serial No.271,690

(Cl. 20D-87) 9 Claims.

'and assemble.

Y vture is mounted in the casing. This core structure comprises a numberof laminations frictionally secured in a recess in the casing by aleafspring. A shading coil element encircling a portion of the corestructure adjacent its pole face serves to retain an energizing windingon a leg of the magnetic core and also co-operates `with the casing forfurther positioning and mounting these parts in the casing, the use ofcomplicated and expensive fastening elements being avoided.

In assembly, the core laminations are Stacked and inserted in the recessor depression in the casing. 'I'he leaf spring is then inserted into therecess beside the laminatipns to hold them j together. The energizingwinding wound on a spool is placed over the leg of the core, and theshading coil element is inserted in suitable slots in the pole faces ofthe core to clamp the laminations together. Self-tapping screws whichcooperate with the shading coil element are then screwed into the casingto ysecure and position the whole'magnetic structure.

For mounting a movable contact and an armature which cooperates withthecore structure, a

` resilient strip is provided which is secured to a terminal v memberfastened in the casing. the

terminal member also serving to secure the en- Y ergizing winding inposition on the core structure. The resilient strip has a trifurcatedmovable end comprising a pair of outer prongs and a central prong all ofwhich extend across one face of the armature. For securing the armature.

hooked ends are provided on. the outer prongs and are inserted inapertures at one end of the armature, the amature being free for limitedpivotal movement with respect to the outer prongs. i

The movable contact is carried at the end of thev central .prong andengages a xed contact, the contacts beingl arranged either normally openor normally closed as desired. With normally closed or engaged contacts,the contact pressure is substantially determined by the biasing force ofthe outer prongs minus the opposite biasing force of the central prong.With normally open or disengaged contacts, the `contact pressure isdetermined by the biasing force of the central prong alone. the contactsengaging slightly before the armature reaches its attracted position.

The operation of the relay is quiet due to the fact that the movement ofthe armature is restricted on one end only by the outer prongs. Thisallows the armature to find its own position touching both poles of thecore when the coil is energized. Since the pressure holding the armatureaway from the core is applied by two separate prongs, the armature isfree to rock sidewise a limited amount in order to align itself with thepole faces of the core. Quiet operation of the amature between itsattracted and unattracted positions is enhanced by doubly biasing thearmature. that is, it is biased to the unattracted position by the outerprongs and is biased to the attracted position by the central prong witha. lesser force than that provided by the outer prongs.

Further objects and advantages of my invention will become apparent fromthe following description and for a complete understanding of phenoliccondensation product. In the my invention reference should be had to theaccompanying drawing in which Fig. 1 is a plan view of a switchembodying my invention having normally closed contacts; Fig. 2 is asectional view of the switch taken along the line 2-2 of Fig. l lookingin 'the direction of thearrows; Fig. 3 is a sectional view of the switchtaken along .the line 3 3 oi' Fig. 2 looking in the direction of thearrows; and Fig. 4 is a sectional view of the switch taken along line 44 of Fig. 2 looking in the direction of the arrows; Fig. 5 is adisassembled perspective view of certain oper- (ating parts of theswitch; and Fig. 6 is a sectional view similar to Fig. 4 but showing theswitch provided with normally open contacts.

Referring to the drawing, invention in one form as applied by anelectrical switch of the magnetically operated type enclosed 'inacasing"which maybe made from some suitable plastic insulatingcomposition, suchas, a preferred I have shown my ment of the armature with respect to itsmounting is provided. The central prong 3i is not semagnetic core I4composed of a plurality ofr laminations i5 of suitable magnetic materialstacked together. The connecting portion of the U forms a substantiallyrectangular projection i6 adapted to be inserted into a substantiallyrectangular recess il in the upper wall of the casing lil. An initiallydeformed leaf spring i8 is also inserted in the recess ll along one sideof the projection i6 to bias the stacked laminations i5 together andagainst a side of the recess, frictionally to secure the laminations inthe recess and thereby mounting the magnetic core structure lli in thecasing. The two legs of the U form the two legs i3 and 23 of themagnetic core structure i4 having the pole faces 2i at the extreme endsprovided with the slots 22 therein for receiving a shading coil element23. The inner portion of each of the legs IS and 23 is encircled by theshading coil element 23 which affects the phase angle of the magneticflux at the corresponding portions of the pole faces 2i in a well knownmanner. Preferably, the shading coil element 23 comprises a at'platestamping of non-magnetic material, such as copper, having a pair ofapertures 2li for mounting the element in the slots 22 on the legs i3and 20 of the core structure I6. Extending portions at the sides of theshading coil element 23 are provided with the screw holes 25 forreceiving the self-tapping screws 26 which are threaded into the casingi0 for securing the shading coil element and the core structure inposition. As`illustrated in Figs. 2 and 3, a. spool 21 of insulatingmaterial having an energizing winding 28 thereon is mounted on the legof the core structure' in'- between the bottom of the U andthe shadingcoil element 23, the shading coil element retaining the spool on theleg. Y z

For` operating a movable contact 29 to engage with and disengage from afixed contact 30, I

have provided an armature 3i of suitable magnetizable material which isresiliently supported by a resilient strip 32, preferably of conductingmaterial, for movement from an unattracted position shown in Fig. 2 toan attracted position (not shown), when the energizing winding 28 isenergized. As shown, the armature 3i `comprises a plurality ofsuperposed laminations of magnetizable material secured together by arivet v33 and` having at its right end a pair of apertures 33 extendingtherethrough. The resilient strip 32 is preferably provided with a bentportion at its. left end suitably secured,.such as by spot welding, to aterminal support 35 which extends across the casing I0 and is. fastenedtherein. From the vertex of the angle forming the bend in the resilientstrip 32, the remaining portion thereof extending to the right istrifurcated to form a pair of outer prongs 36 and a central prong 31, insubstantially parallel relationship, which extend across one face of thearmature 3i for supporting and biasing it as described herebelow. Thearmature 3l is secured to the outer prongs 36 by means of the hookedportions 38 at their right ends which are projected through theapertures 34 and bent around the right end of the armature. In thismanner, limited pivotal movecured to the armature but is free formovement relative thereto. i

The resilient strip 32 serves to support, secure and bias the armature3|. The hooked ends 33 of the outer prongs 35 *effectively prevent anyundue longitudinal or side-wise movement of the armature 3| with'respectto the pole faces 2i. The outer prongs 36 are preformed or bent to biasthe armature 3i to its unattracted position shown in Fig. 2, while thecentral prong 3l is preformed or bent to support and bias the armature,when in its unattracted position, to its attracted position with alesser force than the biasing force of the outer prongs, whereby thearmature is held by prong 3l in place in the hooked ends 33 of the prong36. The central prong 3i also carries at its extreme right end themovable contact 29 which, as shown in Fig. 2, is mounted for normalengagement with the fixed contact 3G, that is, normally closed contacts,when the armature 3i is in its unattracted posiltion. However, as seenin Fig. 6, these contacts- 29 and 30 may be respectively placed toprovide normally disengaged contacts, that is, normally open contacts,when the armature is in its unattracted position.

As seen in the drawing, the change from normally closed contacts tonormally open contacts may easily be made by placing themovable contact2S on the opposite side of the central prong 3l and by inverting thefixed contact 3G from its former position to a spaced apart relation forengagement by the movable contact 29, when the armature moves from theunattracted to the attracted position. When normally open contacts areprovided, as illustrated in Fig. 6, a stop projection 39 is preferablyutilized to determine the unattracted position of the armature and themovable contact. As shown, the stop 39 comprises a projection ofvinsulating material supported by the casing -ID and adapted to engagethe right end of the central prong 31 in the unattracted position of thearmature.

Y As best seen in Figs. 1 and 5, the terminal support 35 comprises abody portion l0 bridged across the casing and supported on suitableposts 4i at the sides thereof and a flange portion 42 extending upwardlyfrom the central part of the body portion providing a broad surface uponwhich the bent portionof the resilient strip 32 may -be secured bywelding. The terminal member 35 is preferably secured to the casing byswagingover' the protruding ends of metallic inserts which are insertedin apertures in the casing. Theinsert i3 shown in Figs. 4 and 6 securingthe terminal strip 44 which mounts the fixed contact 30 is illustrative.Circuit connections to suitable conductors are made by means of thescrews 45 threaded into the inserts 43. The body portion 4U of theterminal member 35 also assists in securing the energizing winding 28and spool 2l in place on the leg 20 of the core structure. V'

As viewed in Fig. 1, the circuit of the energizing winding 28 throughthe switch extends from the terminal member 35 through the winding 28and to the terminal screw 45 in the upper right' hand corner of thecasing, The controlled circuit through the switch extends from theterminal member 35 through the central prong'31 and the contacts 29 and30 to the terminal strip 44 in the lower left hand corner of thecasings.

In operation of the switch with normally closed contacts as shown inFig. 2, the contact contact 30.

pressure between the engaged contacts 29 and 30 is substantiallydetermined by the biasing force of the outer prongs 36 minus the biasingforce of the central prong 31, although the weight of the armature 3lhas an effect when the switch is mounted as shown. Energization ofthemagnetic core structure I4 causes the amature to move upwardly to theattracted position and disengage the movable contact 23 from the fixedWith normally open contacts as shown in Fig. 6, the unattracted positionis determined by the stop 39 which limits the downward movement of thecentral prong 31 and the movable contact 29. When the armature 3| isattracted, it moves upwardly, the movable contact 29 engaging the xedcontact 30 which prevents further movement of the central prong 31thereafter while the armature continues its upward movement to theattracted position. The contact pressure between the contacts 29 and 30in this instance is determined by the biasing force of the central prong39 acting substantially alone. Ineach of the above instances, theoperation of the relay ls quiet due to the fact that the armature 3| isfree t align itself with the pole faces 2| of the core I4 by rocking ineither direction, i. e., lengthwise or sidewise.` Lengthwise movement isaiorded by pivoting of the armature Il on the hooked ends 38 of theouter prongs 36. Since the armature 3| is held by two prongs 36 and eachone is free to move independently of the other, the armature can rocksidewise also to align itself with the pole faces While I have shown aparticular embodiment of my invention, it will be understood, of course,that I do not wish to be limited thereto since mam modicationsimay bemade, and I therefore contemplate by the appended claims to cover anysuch modications as fall within the true spirit and scope of myinvention.

What claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric switch comprising switching means, a magnetic corestructure, an energizing v winding on said core structure, an amaturemovable between magnetically attracted and unattracted positions, meansbiasing and supporting saidamature including a plurality of resilientstrips extendingiacross one face of said amature, support means securingone end of said strips. means including al hooked end on one of saidstrips for securing said armature to said strip, said strip biasing saidarmature to said unattracted position, at least one other of said stripsbiasing said armature with a lesser' force to said attracted position,and vmeans including said other strip for operating said switchingmeans. Iv y 2. An electric switch comprising switching means, a.magnetic core structure, an energizing winding cn said ccre structure,an armature movable between magnetically attracted and unattractedpositions, spring means for resiliently supporting said amatureincluding a strip of resilient material secured at one end and having atrifurcated portion at the other end comprising a certr'al prong andapair of outerprongs,

said outer prongs biasing said armature to said unattracted position,and said central prong operating said switching means and biasing saidarmature to said attracted position.

3. An electric switch comprising relatively xed and movable contacts, amagnetic core structure,

an energizing winding on said core structure, an 7 armature movablebetween magnetically attracted and unattracted positions for operatingsaid movable contact, spring means for resiliently supporting saidarmature including a strip of resilient material secured at one end andhaving a trifurcated portion comprising a central prong and a pair ofouter prongs in substantially parallel relationship, said outer prongsbiasing said armature to saidunattiacted position, said iixed andmovable contacts being in normal engagement when said armature is insaid unattracted position, and said central prong mounting said movablecontact and biasing said armature to said attracted position, thecontact pressure between said contacts being substantially determined bythe biasing force ci said outer prongs minus the biasing force of said,central prong on said armature.

4. An electric switch comprising relatively fixed and movable contacts,a magnetic core structure, an energizing winding on said core structure,lan armature movable between magnetically attracted and unattractedpositions for operating said movable contact, spring means forresiliently supporting said armature including a biasing said armatureto said unattracted position, said contacts being normally disengagedwhen said armature is in said unattracted position,` and said centralprong mounting said movable contact and biasing said armature in saidunattractive position to said attracted position with a lesser forcethan the force of said outer prongs, whereby the biasing force of saidcentral prong assists the magnetic force of said core structure tendingto draw the armature to said attracted position until said contacts areengaged, thereafter the contact pressure between said contacts beingdetermined by the biasing force of said central prong.

5. An electric switch comprising a casing of insulating material,relatively Ilxed and movable contacts, a magnetic core structure mountedin said casing, an energizing winding on said core structure, an amaturemovable between magnetically attracted and unattracted positions foroperating said movable contact, a fixed terminal member mounted in saidcasing having a portion serving as a support and another portionfor-securing said energizing winding on said core structure, springmeans for resiliently supporting said armature including a strip ofresilient' material having one end secured to said terminal support andhaving a trifurcated portion at its other end comprising a central prongand a pair vof outer prongs in substantially parallel relationship, saidouter prongs biasing said armature to Vsaicl unattracted position, andsaid central prong operating said movable contact and biasing saidarmature when in said unattracted position to said attracted position.

6. An electric switch comprising a casing of insulating material,relativelyl fixed and movable contacts, a magnetic core structuresecured in said casing, an energizing winding on said core structure, anarmature movable between magnetically attracted and unattractedpositions for operating said movable contact, a terminal member mountedin said casing and having a portion serving as a support, spring meansfor resiliently supporting said armature includinga strip of resilientmaterial secured at one end to said terminal support and having atrifurcated portion at its other end freely movable and comprising acentral prong and a pair of outer prongs in substantially parallelrelationship, means including a hooked end portion on each of said outerprongs and co-operating apertures in said armature for securing saidarmature to said outer prongs, said outer prongs biasing said armatureto its unattracted position, and said central prong operating saidmovable contact and biasing said armature to said attracted position.

'1. The combination with an electric switch of the magnetically operatedtype of a casing of insulating material having a recess in a wallthereof, a magnetic core structure including a plurality of laminationsprovided with a leg porstructure adjacent said pole face, meansincluding a portion of said shading coil element for additionallysecuring and positioning said core structure in said casing, a fixedterminal member mounted in said casing and having a portion serving as asupport, said shading coil element and said terminal member securingsaid energizing winding on said leg portion of said core structure,relatively fixed and movable contacts, an armature movable betweenmagnetically attracted and unattracted positions, spring means i'orresiliently supporting said armature including a strip of resilientmaterial secured at one end to said terminal support and having atrifurcated portion at the other end comprising a pair of outer prongsand a central prong extending across one side of said armature insubstantially parallel relation, and`means including a hooked end onsaid outer prongs for securing said armai laminations forming a U-shapedcore member having its base inserted in said recess, resilient means insaid recess applying a pressure laterally against said laminations so asto press said laminations together, the end of each arm of said U-shapedcore member being provided with a pole face and with a slot extendingtransversely with respect to said laminations, a pole shader plate madeof electrically conducting material provided with separate portionslying in said slots and with a portion extending laterally at each sideof said core member, means detachably securing said extensions on saidplate to said base thereby to clamp said plate and said core member tosaid base,said plate forming a pole shader for both pole faces of saidcore member, an armature, resilient means loosely supporting saidarmature in spaced relation with both of said pole faces, a winding onsaid core member secured on said core member by said pole shader plate,said winding when energized moving said armature into engagement withboth of said pole faces, and switch means operated by said armature.

9. An electric switch comprising a support made of electricallyinsulating material provided with a rectangular recess, a plurality ofstacked laminations forming a U-shaped core member having its baseinserted in said recess, the end of each arm of said U-shaped coremember being provided with a pole face and with a slot extendingtransversely with respect to said laminations, a pole shader plate madeof electrically conducting material provided with separate portions1ying in said slots and with a portion extending laterally at each sideof said core member, means detachably securing said extensions on saidplate to said base thereby to clamp said plate and said core member tosaid base, said plate forming a pole shader for both pole faces of saidcore member, a spring vstrip extending across said pole faces in spacedrelation therewith, an armature loosely secured on said spring strip andnormally held by said spring strip in spaced relation with both of,lsaid pole faces, and a winding on said core member secured on said coremember by said pole shader plate, said winding when energized movingsaid armature into engagement with both of said pole faces, and switchmeans carried by said spring strip.

CARL P. PEPPER.

